The virtual package is a technology aimed to expand the contents of the read-only type recording medium, by creating a virtual package by dynamically combining data recorded on a read-only type recording medium such as BD-ROM, with data recorded on a rewritable recording medium such as a semiconductor memory card or a hard disk. In such technologies, for example, data recorded on a rewritable hard disk is updated such that a work recorded on a BD-ROM can be modified even after the BD-ROM is distributed. More specifically, a provider of movie works can distribute BD-ROMs recording therein copies of a movie work main body, and then can always promote the latest movie works other than this movie work, regardless of the timing of distributing the BD-ROMs, by providing a digital stream of previews of the latest movies via a network.
The technologies related to the virtual package include those recited in the following Patent Documents 1, 2, and 3.    Patent Document 1: Japanese Patent Application Publication No. 2006-109494    Patent Document 2: Japanese Patent Application Publication No. 2007-20211    Patent Document 3: Japanese Patent Application Publication No. 2006-33067